It has been 11 years since the Crimean Peninsula fell under the control of Russia.
Ukrainian President Volodymyr Zelenskyy's recent rejection of recognising Crimea as part of Russia's territory has been lashed out at by US President Donald Trump.
Mr Trump criticised Mr Zelenskyy's statement as "very harmful to the peace negotiations", saying Crimea was lost years ago and "is not even a point of discussion".
What has happened in Crimea since Russia's illegal takeover, and why is it contested?
Here's what we know.
What has happened in Crimea since Russia's invasion?
Crimea has been governed by Russia-backed Sergey Aksyonov since February 2014, after Russia illegally invaded and annexed Crimea.
[Crimea location map]Weeks after the annexation, fighting broke out in eastern Ukraine between pro-Kremlin militias and Kyiv’s forces.
Here are key events between Russia and Ukraine:
Will Crimea be part of Russia-Ukraine ceasefire talks?
Unlikely.
"Crimea will not be a part of negotiations as an independent entity," said Jessica Genauer, a senior lecturer in International Relations at Flinders University, citing that Crimea "is under Russian-backed governance at present".
"However, negotiations between Russia and Ukraine for a peace settlement will need to reach [an] agreement on Crimean governance," Dr Genauer told the ABC.
She added that 55 per cent of Ukrainians were opposed to any territorial concessions to Russia from Ukraine, including Crimea, according to the Kyiv International Institute of Sociology polling in May 2024.
"If Zelenskyy were to formally cede Crimea to Russian control, this would be unacceptable to a majority of the Ukrainian population and would be politically risky for Zelenskyy," Dr Genauer said.
What do we expect next?
Dr Genauer said a temporary cessation of hostilities in the Russia-Ukraine war would likely happen based on the current negotiators, but it "will not lead to a lasting peace".
"[Donald] Trump is primarily concerned about showing his domestic core support base that he can 'get results' in the war between Russia and Ukraine," she said.
"Trump is less concerned about the specifics of those results or whether they lead to a lasting and substantive peace. Trump will, therefore, try to push for any agreement to be reached.
"Realistically, this will be at most a temporary cessation of hostilities."
If that happens, Dr Genauer said Mr Trump would claim the cessation as a "win" for himself and his presidency and would blame any failure to reach a more lasting agreement on Ukraine and Russia.
She said, "The deeper, more intractable issue of territorial sovereignty and control would need to be addressed for a more comprehensive peace agreement to be reached.
"However, Russia and Ukraine stand too far apart on this issue at present for agreement.
"Russia would like Crimea and about 20 per cent of Ukrainian sovereign territory to be officially ceded to Russia — Ukrainians would never agree to such a deal."
Mr Trump told Time Magazine during an interview that Crimea would stay with Russia.
"Well, Crimea went to the Russians," he said, "It was handed to them by Barack Hussein Obama, and not by me," he said.
"It's been with them long before Trump came along. Again, this is Obama's war.
"This is a war that should have never happened. I call it the war that should have never happened."
Why is Crimea significant?
It is strategically significant for military purposes and global transportation.
Russia's Black Sea Fleet is based in Sevastopol, which was leased from Ukraine and gives Moscow access to the Mediterranean.
Russia has frequently used Crimea as a launch pad for missile and drone attacks since its full-scale invasion of Ukraine in 2024, and the Ukrainian military has also fired missiles at Crimea.
On the other hand, the possession of Crimea is key to control over activities in the Black Sea, which is a critical corridor for the world's grain, among other goods.
Crimea's unique position in the Black Sea makes it a strategically important asset for whoever controls it, and Russia has spent centuries fighting for it.
Who lawfully owns Crimea?
Crimea was home to Turkic-speaking Tatars when the Russian empire first annexed it in the 18th century.
The Soviet Union took over Crimea after the Tatars briefly regained independence as a Tatar republic for two centuries.
In 1944, Soviet dictator Josef Stalin deported nearly 200,000 Tatars, or about a third of Crimea's population, to Central Asia, 3,200 kilometres to the east.
Crimea was part of Russia until 1955, when Soviet leader Nikita Khrushchev transferred Crimea from Russia to Ukraine to commemorate the 300th anniversary of the unification of Moscow and Kyiv.
When the Soviet Union collapsed, the peninsula became part of newly independent Ukraine.
ABC/Wires
